In vivo and in vitro response to octreotide LAR in a TSH-secreting adenoma: characterization of somatostatin receptor expression and role of subtype 5

Pituitary ◽  
2010 ◽  
Vol 14 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Federico Gatto ◽  
Federica Barbieri ◽  
Lara Castelletti ◽  
Marica Arvigo ◽  
Alessandra Pattarozzi ◽  
...  
2019 ◽  
Vol 476 (10) ◽  
pp. 1521-1537 ◽  
Author(s):  
Emma J. Goldberg ◽  
Katherine A. Buddo ◽  
Kelsey L. McLaughlin ◽  
Regina F. Fernandez ◽  
Andrea S. Pereyra ◽  
...  

Abstract Alterations to branched-chain keto acid (BCKA) oxidation have been implicated in a wide variety of human diseases, ranging from diabetes to cancer. Although global shifts in BCKA metabolism—evident by gene transcription, metabolite profiling, and in vivo flux analyses have been documented across various pathological conditions, the underlying biochemical mechanism(s) within the mitochondrion remain largely unknown. In vitro experiments using isolated mitochondria represent a powerful biochemical tool for elucidating the role of the mitochondrion in driving disease. Such analyses have routinely been utilized across disciplines to shed valuable insight into mitochondrial-linked pathologies. That said, few studies have attempted to model in vitro BCKA oxidation in isolated organelles. The impetus for the present study stemmed from the knowledge that complete oxidation of each of the three BCKAs involves a reaction dependent upon bicarbonate and ATP, both of which are not typically included in respiration experiments. Based on this, it was hypothesized that the inclusion of exogenous bicarbonate and stimulation of respiration using physiological shifts in ATP-free energy, rather than excess ADP, would allow for maximal BCKA-supported respiratory flux in isolated mitochondria. This hypothesis was confirmed in mitochondria from several mouse tissues, including heart, liver and skeletal muscle. What follows is a thorough characterization and validation of a novel biochemical tool for investigating BCKA metabolism in isolated mitochondria.


2010 ◽  
Vol 78 (6) ◽  
pp. 2370-2376 ◽  
Author(s):  
Louise M. Temple ◽  
David M. Miyamoto ◽  
Manju Mehta ◽  
Christian M. Capitini ◽  
Stephen Von Stetina ◽  
...  

ABSTRACT Bordetella avium causes bordetellosis in birds, a disease similar to whooping cough caused by Bordetella pertussis in children. B. avium agglutinates guinea pig erythrocytes via an unknown mechanism. Loss of hemagglutination ability results in attenuation. We report the use of transposon mutagenesis to identify two genes required for hemagglutination. The genes (hagA and hagB) were adjacent and divergently oriented and had no orthologs in the genomes of other Bordetella species. Construction of in-frame, unmarked mutations in each gene allowed examination of the role of each in conferring erythrocyte agglutination, explanted tracheal cell adherence, and turkey poult tracheal colonization. In all of the in vitro and in vivo assays, the requirement for the trans-acting products of hagA and hagB (HagA and HagB) was readily shown. Western blotting, using antibodies to purified HagA and HagB, revealed proteins of the predicted sizes of HagA and HagB in an outer membrane-enriched fraction. Antiserum to HagB, but not HagA, blocked B. avium erythrocyte agglutination and explanted turkey tracheal ring binding. Bioinformatic analysis indicated the similarity of HagA and HagB to several two-component secretory apparatuses in which one product facilitates the exposition of the other. HagB has the potential to serve as a useful immunogen to protect turkeys against colonization and subsequent disease.


2014 ◽  
Vol 307 (1) ◽  
pp. F25-F32 ◽  
Author(s):  
Fei Wang ◽  
Xiaohan Lu ◽  
Kexin Peng ◽  
Li Zhou ◽  
Chunling Li ◽  
...  

(Pro)renin receptor (PRR) is predominantly expressed in the distal nephron where it is activated by angiotensin II (ANG II), resulting in increased renin activity in the renal medulla thereby amplifying the de novo generation and action of local ANG II. The goal of the present study was to test the role of cycloxygenase-2 (COX-2) in meditating ANG II-induced PRR expression in the renal medulla in vitro and in vivo. Exposure of primary rat inner medullary collecting duct cells to ANG II induced sequential increases in COX-2 and PRR protein expression. When the cells were pretreated with a COX-2 inhibitor NS-398, ANG II-induced upregulation of PRR protein expression was almost completely abolished, in parallel with the changes in medium active renin content. The inhibitory effect of NS-398 on the PRR expression was reversed by adding exogenous PGE2. A 14-day ANG II infusion elevated renal medullary PRR expression and active and total renin content in parallel with increased urinary renin, all of which were remarkably suppressed by the COX-2 inhibitor celecoxib. In contrast, plasma and renal cortical active and total renin content were suppressed by ANG II treatment, an effect that was unaffected by COX-2 inhibition. Systolic blood pressure was elevated with ANG II infusion, which was attenuated by the COX-2 inhibition. Overall, the results obtained from in vitro and in vivo studies established a crucial role of COX-2 in mediating upregulation of renal medullary PRR expression and renin content during ANG II hypertension.


2019 ◽  
Author(s):  
Alexandre Mariotte ◽  
Aurore Decauwer ◽  
Chrystelle Po ◽  
Cherine Abou-Faycal ◽  
Angelique Pichot ◽  
...  

The role of Monosodium Urate (MSU) crystals in gout pathophysiology is well described, as is the major impact of IL-1b in the inflammatory reaction that constitutes the hallmark of the disease. However, despite the discovery of the NLRP3 inflammasome and its role as a Pattern Recognition Receptor linking the detection of a danger signal (MSU) to IL-1b; secretion in vitro, the precise mechanisms leading to joint inflammation in gout patients are still poorly understood. Here, we provide an extensive clinical, biological and molecular characterization of the acute uratic inflammation mouse model induced by subcutaneous injection of MSU crystals, which accurately mimics human gout. Our work reveals several key features of MSU-dependent inflammation and identifies novel therapeutic opportunities, among which the use of topical application of imiquimod to promote interferon-dependent anti-inflammatory action maybe relevant.


2011 ◽  
Vol 2 (1) ◽  
pp. 4
Author(s):  
Jianhao Ke ◽  
Jinwen Wang ◽  
Riqiang Deng ◽  
Lin Lin ◽  
Bei Jinlong ◽  
...  

<p>ORF69 (Ac69) of <em>Autographa californica</em> multiple nucleopolyhedrovirus (Ac<em>M</em>NPV) is conserved in some baculovirus genomes. Although it has been shown that Ac69 has cap 0-dependent methyltransferase activity and is not required for budded virus production in <em>Spodoptera frugiperda</em> Sf-9 cells, its role in occlusion-derived virus synthesis and virus oral infectivity is not known. This paper describes generation of an <em>ac69</em> knockout Ac<em>M</em>NPV bacmid mutant and analyses of the influence of <em>ac69</em> deletion on the viral infectivity in Sf-9 cells and <em>Trichoplusia ni</em> larvae so as to investigate the role of <em>ac69 in the viral life cycle. Results indicated that ac69</em> deletion has little effect on the production rates and morphogenesis of budded virus and occlusion-derived virus in Sf-9 cells. In addition, animal experiment revealed that the deletion mutant did not affect Ac<em>M</em>NPV infectivity for <em>Trichoplusia ni</em> larvae in LD<sub>50</sub> and LT<sub>50</sub> bioassay when administered orally. These results suggest that <em>ac69</em> may be dispensable for viral infectivity both in vitro and in vivo.</p>


Drug Delivery ◽  
2003 ◽  
Vol 10 (4) ◽  
pp. 269-275 ◽  
Author(s):  
M. Thilek Kumar ◽  
C. Rajeswari ◽  
J. Balasubramaniam ◽  
J. K. Pandit ◽  
S. Kant

Blood ◽  
2011 ◽  
Vol 118 (4) ◽  
pp. 1087-1098 ◽  
Author(s):  
Laure Gambardella ◽  
Karen E. Anderson ◽  
Claudia Nussbaum ◽  
Anne Segonds-Pichon ◽  
Tânia Margarido ◽  
...  

Abstract Neutrophils form a vital part of the innate immune response, but at the same time their inappropriate activation contributes to autoimmune diseases. Many molecular components are involved in fine-tuning neutrophil function. We report here the first characterization of the role of ARAP3, a PI3K and Rap-regulated GTPase-activating protein for RhoA and Arf6 in murine neutrophils. We show that neutrophils lacking ARAP3 are preactivated in vitro and in vivo, exhibiting increased β2 integrin affinity and avidity. ARAP3-deficient neutrophils are hyperresponsive in several adhesion-dependent situations in vitro, including the formation of reactive oxygen species, adhesion, spreading, and granule release. ARAP3-deficient cells adhere more firmly under flow conditions in vitro and to the vessel wall in vivo. Finally, loss of ARAP3 interferes with integrin-dependent neutrophil chemotaxis. The results of the present study suggest an important function of ARAP3 downstream of Rap. By modulating β2 integrin activity, ARAP3 guards neutrophils in their quiescent state unless activated.


2000 ◽  
Vol 74 (8) ◽  
pp. 3682-3695 ◽  
Author(s):  
Paula Traktman ◽  
Ke Liu ◽  
Joseph DeMasi ◽  
Robert Rollins ◽  
Sophy Jesty ◽  
...  

ABSTRACT We have previously reported the construction and characterization of vindH1, an inducible recombinant in which expression of the vaccinia virus H1 phosphatase is regulated experimentally by IPTG (isopropyl-β-d-thiogalactopyranoside) (35). In the absence of H1 expression, the transcriptional competence and infectivity of nascent virions are severely compromised. We have sought to identify H1 substrates by characterizing proteins that are hyperphosphorylated in H1-deficient virions. Here, we demonstrate that the A14 protein, a component of the virion membrane, is indeed an H1 phosphatase substrate in vivo and in vitro. A14 is hyperphosphorylated on serine residues in the absence of H1 expression. To enable a genetic analysis of A14's function during the viral life cycle, we have adopted the regulatory components of the tetracycline (TET) operon and created new reagents for the construction of TET-inducible vaccinia virus recombinants. In the context of a virus expressing the TET repressor (tetR), insertion of the TET operator between the transcriptional and translational start sites of a late viral gene enables its expression to be tightly regulated by TET. We constructed a TET-inducible recombinant for the A14 gene, vindA14. In the absence of TET, vindA14 fails to form plaques and the 24-h yield of infectious progeny is reduced by 3 orders of magnitude. The infection arrests early during viral morphogenesis, with the accumulation of large numbers of vesicles and the appearance of “empty” crescents that appear to adhere only loosely to virosomes. This phenotype corresponds closely to that observed for an IPTG-inducible A14 recombinant whose construction and characterization were reported while our work was ongoing (47). The consistency in the phenotypes seen for the IPTG- and TET-inducible recombinants confirms the efficacy of the TET-inducible system and reinforces the value of having a second, independent system available for generating inducible recombinants.


2010 ◽  
Vol 95 (5) ◽  
pp. 2343-2350 ◽  
Author(s):  
Jean Claude Reubi ◽  
Beatrice Waser ◽  
Renzo Cescato ◽  
Beat Gloor ◽  
Christoph Stettler ◽  
...  

Abstract Context: Somatostatin receptor subtype 2 (sst2) is widely expressed in neuroendocrine tumors and can be visualized immunohistochemically at the cell membrane for diagnostic purposes. Recently, it has been demonstrated in animal sst2 tumor models in vivo that somatostatin analog treatment was able to induce a complete internalization of the tumor sst2. Patients and Methods: In the present study, we evaluated whether sst2 expressed in neuroendocrine tumors of patients treated with octreotide are also internalized. Tumor samples were assessed in patients that were treated with various octreotide modalities before and during surgery and compared with tumor samples from untreated patients. Sst2 immunohistochemistry was performed in all samples with three different sst2 antibodies (R2-88, UMB-1, and SS-800). Sst2 receptor expression was confirmed by immunoblotting and in vitro receptor autoradiography. Results: Patients receiving a high dose of octreotide showed predominantly internalized sst2, and patients with a low dose of octreotide had a variable ratio of internalized vs. membranous sst2, whereas untreated patients had exclusively membranous sst2. The internalized sst2 receptor corresponded to a single sst2 band in immunoblots and to sst2 receptors in in vitro receptor autoradiography. Although generally found in endosome-like structures, internalized sst2 receptors were also identified to a small extent in lysosomes, as seen in colocalization experiments. Conclusion: It is the first evidence showing that sst2 receptors can be internalized in sst2-expressing neuroendocrine tumors in patients under octreotide therapy, providing clues about sst2 receptor biology and trafficking dynamics in patients.


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